Hydraulically operated mobile digging machine



G. DAVIS Nov. 22, 1960 HYDRAULICALLY OPERATED MOBILE DIGGING MACHINE Filed Feb. 1, 1956 INVENTOR. Geo/" e DOV/s @M 4 7 TORA/FK ture.

HYDRAULICALLY OPERATED MOBILE DIGGING MACHINE George Davis, Benton Harbor, Mich., assignor to Davis Engineering Incorporated, Benton Harbor, Mich.

Filed Feb. 1, 1956, Ser. No. 562,883 1 Claim. (Cl. 214-138) This invention relates to improvements in hydraulically operated mobile digging machine. of this invention are:

First, to provide a mobile digger or excavating machine which is relatively simple and inexpensive to manufac- Second, to provide an excavating machine having an articulated boom and bucket arm and bucket which are operated by hydraulic rams positioned on the top of the boom and arm to be clear of dirt in the excavation.

Third, to provide a hydraulically operated digging apparatus which will operate close to a supporting mobile carriage.

Fourth, to provide a support and operating mechanism having an excavating bucket which will move the bucket through a relatively wide range of movement both horizontally and downwardly to provide a wide range of digging operation with a supporting boom of minimum length.

Fifth, to provide a digger with articulated boom, bucket arm and bucket that are separately actuated by hydraulic rams that are generally alined so that each ram con tributes to the digging force and movement applied to the bucket and so that axial forces in the rams are opposed and transmitted mainly by the rams instead of being transmitted through the boom.

Other objects and advantages of the invention will be apparent from a consideration of the following description and claim. The drawings, of which there is one sheet, illustrate a highly practical form of the excavating machine.

Fig. 1 is a fragmentary side elevational view of a mobile carriage with the excavating apparatus of the invention mounted thereon.

Fig. 2 is a transverse cross sectional view taken along the plane of the line 22 in Fig. 1.

Fig. 3 is a top plan view of the anchors for the hydraulic rams at the middle of the main operating boom.

Fig. 1 illustrates a mobile carriage 1 having read wheels 2. The carriage may be self driven or towed by any desirable means not illustrated an provides a circular support 3 having a turn table 4 that can be rotated through 360 degrees to face in any direction from the carriage. Mounted on the turn table is an internal combustion engine, a portion of which is indicated at 5. The engine is connected to a pump 6 for delivering hydraulic fluid under pressure. A series of control valves 7 for regulating the supply of hydraulic fluid to different using elements are mounted on the turn table within an operators cab 8. The structure thus far described is well understood in the heavy machinery art and so is not described in greater detail.

Mounted on the top of the turn table 4 is a pivot 9 supporting the inner end of a main boom 10. The boom 10 is angular in shape having a downwardly otfset outer end portion 11. Both portions of the boom are con- The principal objects 2,951,106 Patented Nov. 22, 1960 veniently made of I beam stock as is indicated in Fig. 2 with the web of the I beam disposed transversely of the boom. The joint between the inner and outer ends of the boom is reinforced by triangular gusset plates 12 that project above the boom and support a cross tube 13. The tube 13 is welded to the gusset plates and transversely reinforces them. Where desired or necessary the upper edges of the flanges of the I beam may be connected by cover plates 14 to strengthen the boom or to .keep dirt from collecting in the top of the boom.

Projecting upwardly from the front end of the turn table 4 is an anchor bracket 15 having a pivot 16 on its upper end. The pivot 16 rockably supports the inner end of the cylinder 17 of a hydraulic ram. The piston 18 of the hydraulic ram is extended and pivotally connected at 19 to ears 20 rigidly mounted on the tube 13. It will thus be seen that the ram 17, 18 will function to move the boom from the depressed full line position illustrated to an intermediate position indicated by the dotted lines'at A and to the elevated position indicated by the dotted lines at B.

The outer end of the end portion 11 of the boom carries a pivot 21 on which a bucket arm 22 is swingably supported intermediate of the ends of the arm. The upper or inner end of the arm 22 is pivotally connected at 23 to the piston 24 of a second hydraulic ram having a cylinder 25. The end of the cylinder 25 is pivotally connected at 26 to ears 26A on the opposite side of the tube 13 from the cars 20. Extension and retraction of the piston 24 thus swings the bucket arm 22 through an are about the extreme outer end of the boom. It will be noted that the connections of the ram 18 and cylinder 25 are close to the opposite sides of the tube 13 so that forces created by one cylinder are transmitted directly and primarily to the other cylinder to jointly effect the movement of the bucket arm. Simultaneous extension or retraction of the two rams speeds the movement of the bucket arm and the force applied to the bucket arm is greater than the force developed by either cylinder alone.

A digging bucket 27 having an open end 28 with a digging edge or lip 29 is pivotally connected at 30 to the outer or lower end of the bucket arm 22. The pivot 30 is positioned along the opposite edge of the open end of the bucket from the digging lip 29. Spaced inwardly of the bucket from its open end but on the outside of the bucket is a pivot 31 to which the piston 32 of a third hydraulic ram is connected. The cylinder 33 of the third ram is pivotally connected at 34 to the bucket arm 22. The ram 32, 33 is thus operative to swing the bucket 27 in either a scooping inward motion or an outward emptying motion about the pivot 30. The ram 32, 33 is generally alined with the ram 24, 25 to further increase the speed and force of movement of the bucket.

Flexible conduits connecting the several rams to the control valves 7 are indicated at 35 and are conveniently housed within the upper channel of the I-beam section of the boom. The motion of the boom 10, bucket arm 22, bucket 27 about the several pivots under the selective operation of the three hydraulic rams will be readily apparent. The bucket has a relatively wide range of motion both vertically and horizontally and will move in a relatively horizontal manner to scoop out a wide area at the bottom of an excavation. The boom is easily assembled and constructed in any desired strength from standard structural steel shape so that the excavator can be manufactured at a minimum of expense. All of the rams are on the top of the boom and the bucket arm where they are least liable to be fouled by dirt from the excavation.

sas-new and :isdesired to be secured by Letters Patent .is:

In a mechanical digger having a turn table adapted to be mounted on a carriage, and an operators station alid 1 controls mounted on said talile, afilongitudinaliy angledlboom' pivoted -at--one end v(m -said table with': 'the -angle of the boom 'fa'cing downwardly, said boom having *an H-shape'd cross section with: its side' flanges arran-ged vertically "and with "the pivotal connection to I? the iatab-le *extending through :said :fianges, *spaced bracket plates lapped upon andsecured to -the outersides of 'said'ifianges and projecting upwardly 'from an intermediate portion of said boom at the angle-of the boom, "another pivot on said table spaced vertically =from -thel' pivot of the f-boorn a -tube extending rigidly l between gsaid ibracket -plates aud -spacedfrom the=a-xis of the boom,-a first hy- 'draul'ic' ramhaving its cylinder-and piston extensibly "connected "between said other pivot on the'tableand a'first gpivot onsaidtube, 'a"bucket pivoteddntermediate of its ends to the swinging end of'said'boom"with'the pivot of thearrnr. supported by the ,side'fianges 9f the boom'to swingin the plane of the 'boom, a secondipivot ionsaid tube closely adiacent the first pivgt .on-the tube,

a second hydraulic ram having its cylinder and lame);-

lensibly connected between the .other end ,Qf vsaid lhuttket arm and said second pivot fla bucket pivoted at one side of its mouth to the other end of said bucket arm and having a digging lip on the other side of its open end, a third hydraulic ram having its cylinder and piston extensibly connected between a pivohon said bucket arm and a point on the back of sa'idbuc'ket spaced from the open :en'ddf the bucket, .a source of ihydraulicfluidunders pressure on said table, and hydraulic conduits and controls connecting tsaidlrams, to said source for selective operation of said rams.

Rferencesrfited finithe dile of this: patent UNIT-ED 1 STATES PATENTS 

